21982033 has 6 divisors (see below), whose sum is σ = 22593606. Its totient is φ = 21386592.

The previous prime is 21982019. The next prime is 21982039. The reversal of 21982033 is 33028912.

It can be written as a sum of positive squares in 3 ways, for example, as 11888704 + 10093329 = 3448^2 + 3177^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21982033 is a prime.

It is the 4689-th Hogben number.

It is a junction number, because it is equal to n+sod(n) for n = 21981992 and 21982010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21982039) by changing a digit.

It is a nontrivial repunit in base 4688.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6660 + ... + 9397.

It is an arithmetic number, because the mean of its divisors is an integer number (3765601).

Almost surely, 2^21982033 is an apocalyptic number.

It is an amenable number.

21982033 is a deficient number, since it is larger than the sum of its proper divisors (611573).

21982033 is an equidigital number, since it uses as much as digits as its factorization.

21982033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16131 (or 16094 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21982033 is about 4688.5000799829. The cubic root of 21982033 is about 280.1276331383.

The spelling of 21982033 in words is "twenty-one million, nine hundred eighty-two thousand, thirty-three".